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<html lang="en">
<head>
    <meta charset="UTF-8">
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    <title>Document</title>
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<body>
    <script>
        // 1. 判断当前对象是否为某个实例
        let d = new Date();
        let arr = [];
        console.log(arr instanceof Array);//true
        console.log(d instanceof Date);//true
        console.log(arr instanceof Date);//false

        // 2. 判断是否为数组
        console.log(Array.isArray(arr));//true
        console.log(Array.isArray(d));//false
    </script>
</body>
</html>